Working Papers

Economics of Evidence and Proof

In the Anglo-American common law legal system, the law of evidence regulates the fact-finding phase of the adjudication process, primarily by specifying the content and form of information that a litigant (or anyone else, including a judge) may present to factual decision-makers, which is referred to as the "admissibility" question. There is no law of "proof" per se, but there are doctrines that specify burdens of proof in both of two senses. First, the burden of production identifies the party required to come forward with evidence on a particular fact in dispute. Second, the burden of persuasion is the degree of certainty by which the finder of fact must decide, ranging from a simple preponderance of evidence through various intermediate levels to "beyond a reasonable doubt."

Outside of common law legal systems, there is no separate body of evidence law as such. In those nations following the civil law system, the fact-finding process largely is left to the discretion of the judge. This comparative distinction reflects deeper institutional differences across legal traditions.